Just got an iPad 2 (not the Retina display model) on Friday and LOVE it! Except it keeps giving some kind of "alert" every now and then like it's some kind of notification but no notification messages are appearing like they do on my iPhone! It's a pretty, chime-like sound, but I wish I knew what it's trying to tell me!

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic